公 surface BD=1./cc Compaction BU=18gIcc Layer Wt: not= vol BD =1.6g/cc 1.29/cc
土壤孔隙数量 2计算土壤重量( AFS---acre furrow slice) AFS=面积(么)士层厚度(耕层20cm)×pb 667×10×20×1.15=15×10(g)=150()=30万斤) 亩地农田耕层土壤重约为30万斤左右。 3.计算土壤个组分的数量 4.计算土壤储水量和灌溉定额。 5.计算土壤孔隙度
一.土壤孔隙数量 2.计算土壤重量（AFS—acre furrow slice) （万斤） 面积（么） 土层厚度（耕层 ） 6.67 10 20 1.15 1.5 10 ( ) 150( ) 30 20cm 6 8 b = = = = = g t AFS 一亩地农田耕层土壤重约为30万斤左右。 3.计算土壤个组分的数量 4.计算土壤储水量和灌溉定额。 5.计算土壤孔隙度
Mixture of air, water 容重和比重比较 pore space Bulk minerals and Density organic Particle matter Density Solids Comparison of Bulk Density and Particle Density In a soil profile, one cubic centimeter If all the solids were compressed to the (10cm) appears like this bottom. the cube would now look like this It contains solids and pore spaces, and the whole cm3132 Half contains the pore spaces has a mass of 1.32g Half contains the solids (Notice the Volume change!) T o caculate Bulk Density of the soil To calculate Particle Density of the soil Volume= 1. 0cm3 Mass =132 Volume=0.5cm3 Mass= 1.32g (Solids and Pores) (Sieved Solids only) (Solids only) (Sieved Solids only) Mass of Dry soil Mass of solids Bulk ensI Volume of soil Density s 320 Particle Volume of solids (Solids and Pores) THerefore THerefore: Bulk 1.32 1.32 =1.32g/cm3 Particle 2.64g/cm Density 1.0 Density
容重和比重比较